Pyrovus - 8-4-2004 at 00:22
Over the last few days I've been making sodium ethoxide by electrolysis of sodium chloride in ethanol: ie 2NaCl + 2C2H5OH ->2C2H5ONa + H2
+Cl2. Anyhow, the only material I've had lying around to use for electrodes have been iron paperclips - incredibly bad, I know, iron's quite
annoyingly reactive. Anyhow, as a result I have brown red gunk at the bottom of the container, which could either be iron(III) chloride or ethoxide.
But which one? I tried google for a while, but found nothing about iron ethoxide or it's properties. I guess my question is, is anybody here
familiar with iron ethoxide and its properties, in particular whether or not it's likely to precipitate from an ethanol solution?
darkflame89 - 8-4-2004 at 04:29
That red gunk might have been Fe(OH)3 or Fe2O3. Dunno, but i dun think the electrolysis might not be so straight forward as to give you iron
ethoxide.( I dunno, i know nothing but organic electrolysis)
But as you said iron is damn reactive, i think you have iron oxide or iron hydroxide sitting there now...
[Edited on 8-4-2004 by darkflame89]
Tacho - 8-4-2004 at 06:27
I strongly advise you to use two containers and a salt bridge. You get (hopefully) clean sodium ethoxyde in one container and a dirty mess in the
other.
Did you see my posts about this very subject some time ago? I used copper wire electrodes, methanol and sodium acetate. The catholyte (the liquid
where you stick the negative electrode, where the methoxyde should form) was clean and alkaline after some time.
[Edited on 8-4-2004 by Tacho]
KABOOOM(pyrojustforfun) - 12-4-2004 at 20:07
chlorine reacts with ethanol oxidizing it to acetaldehyde (EtOH + Cl<sub>2</sub> <s> ></s>
Me-CHO + 2HCl) . further chlorination of this yields chloral (Me-CHO + 3Cl<sub>2</sub>
<s> ></s> Cl<sub>3</sub>C-CHO + 3HCl) .
oh.. hold on... NaCl is insoluble in EtOH!
Pyrovus - 12-4-2004 at 22:56
It is actually slightly soluble in ethanol, I don't know the exact figures, but enough that a reaction is observed to occur.
convienient sodium ethoxide preparation
xxxxx - 21-5-2004 at 13:09
there is a us patent from the 1920's, #1,9??,???, which i have used to prepare sodium ethoxide. for a two mole batch 80 grams of naoh is placed
in a one liter glass vessel set for distilling. 400 ccs ethanol is added and a line is drawn on the glass with a marker. then 100ccs of toluene is
added and gently distilled untill the level of the liquid reaches the line. then more toluene is added like so until the reaction is complete, about 4
or 5 times in 2 or 3 hours. reaction is simple disproportionation driven to completion by removal of water as the lower boiling water-ethanol-toluene
ternary azeotrope (77.5?c). if you have the figures for the composition by percent for this azeotrope maybe you could add the correct amount of
toluene at the beginning. it is important to minimize exposure to the atmosphere or your product will discolor (orange), although you do not need an
inert atmoshere to get a pure white product. patent says all alcohols besides methanol will work. possibly sodium ethoxide in methanol will gradually
disproportionate to sodium methoxide due to sodium methoxide being insoluble.